1. Field of the Invention
This invention pertains generally to systems for filtering water, and more particularly to an apparatus for cleansing water in aquatic ponds through the use of aerobic bacteria supported in a plasticized media.
2. 2 Description of the Background Art
Aerobic chambers have been widely used in the treatment of sewage and other liquid or liquified wastes. By diffusing air into the treatment chamber, conditions are created which promote the growth of aerobic bacteria which is efficient at digesting and degrading a variety of influent wastes.
It is also known that the efficiency of an aerobic treatment chamber can be increased by placing a bacteria support medium therein. Typical support media include a plurality of discrete irregularly shaped bodies, similar bodies of regular shape which are loosely packed, honeycombed structures, sheets of tangled rigid plastics, wire-like filaments or strips, gravel, and other solid media through which liquids can flow. As the surface area of the support medium increases, more bacteria can be supported because of the higher ratio of surface area to volume.
U.S. Pat. No. 4,717,519 issued to Sagami on Jan. 5, 1988, discloses a bacteria bed for use in an aeration tank. The bacteria bed contains multiple loops of fiber made from a thermoplastic material such as polyvinylidene chloride which has a high bacteria holding area. U.S. Pat. No. 4,810,385 issued to Hater et al. on Mar. 7, 1989, discloses a sock fabricated from a coarse, porous material such as burlap or canvas, or using a plastic container with openings, to house a bacterial culture for degrading waste or other compounds in a collection system. U.S. Pat. No. 4,908,128 issued to Chiba on Mar. 13, 1990, discloses using plasticized filaments to form a support medium for bacteria in sewage treatment plants. Two separate media having different surface area to volume ratios are assembled to form a bacteria bed. The media are selected to have open weaves which are more conducive to growth of higher order bacteria which are able to digest sludge of lower order micro-organisms. U.S. Pat. No. 4,263,142 issued to Burton on Apr. 21, 1981, discloses a filtration system having a plurality of cartridge filters buried in the soil. Each cartridge is cylindrical in shape and has end caps, one end cap having an inlet line and the other having an outlet line. The end walls also have multiple holes through which clusters of bark fibers project. Influent water passes through the bark fibers which serve to attract and hold nutrient deposition in the water in the form of colloidal wastes, single-celled bacteria, phytoplankton and the like while at the same time providing a safe habitat for minute animal organisms capable of feeding thereupon. Japanese No. 1,218,690 discloses a filtration systems that uses anaerobic bacteria.
U.S. Pat. No. 4,411,780 issued to Suzuki et al. on Oct. 25, 1983, discloses a sewage disposal plant using fibrous filters. U.S. Pat. No. 3,700,590 issued Oct. 24, 1972, discloses a system to separate organic solids from liquid waste using micro-biological communities and fibrous filters. U.S. Pat. No. 3,238,124 issued to Burton on Mar. 1, 1966, discloses a method and apparatus for treating waste liquids using fibrous filters. EPO 359,969 discloses fluid filtration using plastic strips coated with active carbon and bacteria bunches. German 3,812,149 discloses filtration by repeatedly pumping liquid through bacteria-holding inserts.
The foregoing patents disclose a variety of methods and systems for liquid filtration and biological control of waste. Those methods and systems are, however, bulky and expensive for use in aquatic ponds commonly used in landscaping, and some present hazards to fish and wildlife. There is, therefore, a need for a simple, reliable, inexpensive and environmentally safe filtration device for use in aquatic ponds, which utilizes high concentrations of aerobic bacteria to digest or degrade waste products. The foregoing patents reflect the state of the art of which the applicant is aware and are tendered with the view toward discharging applicant's acknowledged duty of candor in disclosing information which may be pertinent in the examination of this application. It is respectfully stipulated, however, that none of these patents teach or render obvious, singly or when considered in combination, applicant's invention herein.